SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b778b33190f7286ac9251d82128227ed9d28a0db22df36b287bf2708f2824bf' 
  AND token = 'XVn2uPxsVss75gGHCfcomJkkhYTTXNQ49ADXJX9CuVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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