SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8779c1fedf10d86a61afbade8ef2b82c060fb4339867b42266e6d20f98ef0d1' 
  AND token = 'f+zef5HR6BoUSFHjHRwGwfGSoTpFOUvOnEC2/lGYm0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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