SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28cabdf332f96bb801df608e975e425234e485999dde0a64eca0439f1d6bdb2e' 
  AND token = 'nDFOAZKNHTp5oY1tVI4WYFpwGhUREFyInRENpUQy+ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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