SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '086ea73dbb31a56efc299f65a5930a857f0519af24d78015dada2baa906c81e4' 
  AND token = 'VF0ZQdYgrFsvmf7cnq3IvAUqegzVhkT5QB4BzOFuk0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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