SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc7250e83462eeeef743c30c0d61615417adde947b3d60ea1e59375cbc931fac' 
  AND token = '25TWsFS/Gb8JzXCDrnMEHWfhAUD/Om/m0oLzAdtgAiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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