SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ec56848a00e96721d691da46e599576993aba8d3c5aa5e95b20774d3f0101bd' 
  AND token = 'vkwHZAYA0Yx9x41rX4BECID1b8mgsC0jwV/qILa+2Ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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