SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '818864752025bec847dbeb3ff7cf539dd46ca3eef78c90f53ab84044c8e66955' 
  AND token = '8TgZYOS3BGPioWYidKt/ULXHE2Kq6OZ4rfAcYbeGUE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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