SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad877d9ba6c2a6083b47b3875baaa65dc6399224f9a7022bd632c8306a763538' 
  AND token = 'vPHwJr6sbIbIOnXqfXW54v0BANi3hX98u0cw+NZS1Og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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