SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09edbd3d74b0d60ec51b0724de0c15e042e2a2097bc503e946dbcf0afd27b466' 
  AND token = 'Ha7yGZEy7+mWW8qiFNra+HL+QqBjFLrkTKEWdZKqri4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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