SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36d7ee86271e29620fc00226a565cfd6d1cff4d043b29f2bc733c8606343be13' 
  AND token = 'CNjvggIUigMTbJdfkz382+ot/Yr7GVnj25oTWIqIkEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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