SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d0c48512f1d26c25d24e179516a1963fc2075574fdcb836c0e2a74db399369e' 
  AND token = 'Uc8gl7p0GH4+r/6+qescVBVadCMoDBquXrQXll4Dl/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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