SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adde42d8f2ab9e83ae8ea50b0fb4a2831be5653c3d71a68eefa818ba75be2f4f' 
  AND token = 'wD157t2YomcZngsAGFtV58GRiRTSBPCBbYf4G7FlLWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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