SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccbdfd604dd8d3272ba16dc7a80274c5da158aba966d0ada10dc27c113d0883a' 
  AND token = 'XVZtm0wHyefIfNlEvV7RRV4rYCIUp+G0pGrXxwU7XZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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