SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c7119dfebd351afe0aa1adc208de7206a5e521e3f18a49b3216f8151c88f034' 
  AND token = 'hL0wornXI4h/klh2JJaPHPy0mE69c61Q3tofNVvLDHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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