SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5afdc49ffc9d0674e04accad5150cc23b068c495e5237ca6ff1d11931d8bd75b' 
  AND token = 'mSrKE4XAiQDVTro2QXbcGheLkhC3LB2G1CO8aZo6VBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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