SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45cf5ec616f4d94d8083f5db2db3d27ce3a6c03fcf9e8cb1b0813172a54e0c3b' 
  AND token = 'PhrW9e49M4S5e14TpgLLUA5RSqAqNRNGOm2WYCsnu9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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