SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd123b80e8b746ed13ab5f713e5c03e7476de56e6026708181901cc50f29336e7' 
  AND token = 'ksw1Q2bBa5uEQvEdWJZZ/INVWBgDQtmhyAzi8Q9WYG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}