SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bef82c48a54d050b397782c691bd81bfba02be61f021721d11c52cf2611d97a' 
  AND token = 'FkE1/CQ3tGytDhDdb0okuixRLQTjQpjUabkx3LZ2GcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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