SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aca9d92415457d11253178ad0e0c3aff355fe85ce10e100a60496acbdd5f6803' 
  AND token = 'znSekLiWtJ2Bs+ybiQ/iZ0kF9VyPBRThCtO2RvOR5/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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