SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd93c20408ccee4bab9158ccc31b00d17f53aaf54a083c9f154314ac96e50adcd' 
  AND token = 'rzYBGGhLe6iPqv4Chu79IJU+1sVsxwi28/tZsqQbyNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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