SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2978bb1442753abd1c8e642e9af0d14329bc251784c8e0c5e1d91182e5b8d513' 
  AND token = '1g+bW8IEMv+iPQg3s9l2/2ARALv1EQ/HC/wiWDeBp/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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