SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '820eaacd25d60d600ce6da7b2dfb3852f00701f5872e11e32a1d9af689dd20c6' 
  AND token = 'TYOKKx4u4rWvmmiJUOPxgdxTYNdjv8qas6bd06weIRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}