SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b231cc988a517b5543fec85b4f46631fce4479d3ae0b32d2d482b0a163209ef' 
  AND token = 'ERpPXQLDpkY2z3HfweDjjDK++JDMIXNNPtLAXRZjjts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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