SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7077f3609d31d8c452742ca82297502620fc7a6066af49e656b4fabe4239f2c' 
  AND token = '+t/2x2BqfYanQAxgve41GI/O/HxonzDNyiDglCwyJWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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