SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd29e4f9eb85da2e0276410553f81c470b4f3ee4c938eb2a9f9a310b990c9a9c2' 
  AND token = 'TRQXrLONjzAV6C5Yn7dlWKsypbXYxhjx5Fp3mPv+wA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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