SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37310c2047edc665ff8f71404ab136297d4c90e545e40b31624d731ae6cb32e9' 
  AND token = 'cTPN+otKOcq26yhgREJLjwjJQVo+BwTQXSnCE/jlXYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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