SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcf5972e2a6931a60fb4c6d87143f543c475ebc9927c51aea39a76f1f4db2b33' 
  AND token = 'vg2LPjHQCSdzqivZqblzTAMqI8ezYZUHLDi0AHXTs78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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