SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66c0e3d3abff16aa1f3c92d1b87d54dfb8ad3d1acea1367bff3ef08c6dcb68ef' 
  AND token = 'SR0lq2LLoemcQDEeNxIOiQOB7dOOFJzw+mQ92hIm9Ns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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