SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a2ec2d05079c75d845c17a59da89c0412304093deb0e525fd543c3d6d573e5' 
  AND token = '9XhmQW1Ic9fO0jB99q0jV+cRYL/mJAKdJ6KT535YE5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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